为了研究文丘里空化器内非定常空化流动诱导的能量特性，构建了一种评估空化能量指标的物理模型，并基于Wall-Adapting Local Eddy-Viscosity(WALE)亚格子模型的大涡模拟方法(LES-WALE)和Schnerr-Sauer空化模型，对文丘里空化器内的空化流动特性进行了数值分析，研究了 3种空化阶段下(σ为0。76，0。51和0。26)文丘里空化器内空化能量分布规律。研究表明:LES-WALE湍流模型和Schnerr-Sauer空化模型联合的数值计算方法可以对文丘里空化器内片状空化对称脱落及云空化溃灭的细节进行精确捕捉;随着空化数的降低，文丘里空化器内空化能量呈现范围及对应数值逐渐增大，在不同空化阶段下，计算域内空化能量的极值发生在片状空穴末端位置处;沿着整个文丘里空化器壁面，其喉部与扩散管连接处存在的空化能量最高，表明该处极易受到空化的破坏作用。研究结果为以文丘里空化器为典型代表的水力空化装置空化能量特性研究提供了一种有效的数值计算方法及能量评估指标。
Development and analysis of energy index for unsteady cavitation flow in a Venturi cavitator
In order to study the energy characteristics induced by the unsteady cavitating flow in a Venturi cavitator,a physical model was developed to evaluate the cavitation energy distribution index.Based on the large eddy simulation method combined with the wall-adapting local eddy-viscosity(LES-WALE)sub-scale model and the Schnerr-Sauer cavitation model,the cavitating flow in a Venturi cavitator was numerically analyzed.The cavitation energy distribution in the Venturi cavitator was studied under three different cavitation stages(σ=0.76,0.51,and 0.26).The study results show that the numerical method(i.e.,the LES-WALE turbulence model and Schnerr-Sauer cavitation model),can accurately capture the details of the symmetrical detachment of sheet cavity and cloud cavitation collapse in the Venturi cavitator.As the cavitation number decreases,the range and corresponding values of cavitation energy in the Venturi cavitator gradually increase.At different cavitation stages,the maximum value of cavitation energy in the calculation domain occurs at the end of the lamellar cavity.Along the entire wall of the Venturi cavitator,the highest cavitation energy occurs at the connection between the throat and the diffusion tube,indicating that this area is highly susceptible to cavitation damage.This article provides an effective numerical model and evaluation index for the assessment of cavitation energy characteristics of hydraulic cavitation devices,represented by the Venturi cavitator.
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维普
